We should feel good when we wake up, not tired and exhausted," said Michael Decker, Ph.D., an associate professor at Georgia State University and spokesman for the American Academy of Sleep Medicine. "That may indicate that something is happening during sleep that we're not aware of."

Sometimes it's not just an issue of not getting enough sleep -- it's a matter of getting good quality sleep, Decker said. Poor sleep quality has been linked in studies to increased inflammation (which can lead to heart disease and stroke), high blood pressure, and increased blood glucose levels and insulin resistance among people with Type 2 diabetes. Getting good, quality sleep -- on the other hand -- is linked with a longer life, PsychCentral reported.

Sleep quality "is important -- it's not not just the duration of sleep, but the quality that determines health outcomes," he said. "We feel better when we sleep for the right amount of time. That's the foundation of where to start."

Take a look at some everyday factors that could be impacting how well you sleep.

LonelinessLoneliness isn't just an issue of the heart and mind -- it's also an issue of sleep, a new study shows.

The small study of 95 adults in South Dakota shows that people who perceived themselves as lonely had more fragmented sleep (which affects sleep quality, but not total sleep amount) than people who didn't think they were lonely. The findings mirror a 2002 study that showed that college students who felt lonely also had more fragmented sleep.

High AltitudeHigh altitudes can also impact sleep, leading to "increased awakenings, frequent brief arousals, marked nocturnal hypoxemia [low blood oxygen], and periodic breathing," according to a 1999 review article in the journal Sleep and Breathing.

Even though most of us don't live in extremely high-altitude areas of the world, nor are we all world-class climbers who regularly scale tall mountains, some people will still experience fragmented sleep if they are spending just a few days in a higher-than-normal altitude area (say, Denver, Colo.) or trying to sleep on an airplane, Decker said.

Sleeping With FidoVeterinarians already advise against sleeping with pets because of the risk of contracting diseases. But sleeping with pets can also take a toll on your sleep quality.

A 2002 study conducted by researchers from the Mayo Clinic shows that 53 percent of pet owners reported they had disrupted sleep every single night, although only 1 percent of the pet owners said that their sleep was interrupted by more than 20 minutes a night because of the pet, ScienceDaily reported.

In addition, 21 percent of the pet owners said their dogs snore at night, and 7 percent said their cats snore at night.

"Pets in the bedroom can disrupt sleep because of the noise they make," Decker said.

Working The Night ShiftDecker explained that the problems that come with working during the nighttime and sleeping during the daytime occur because of our body's sensitivity to light, and the cues we take from light to signal sleep time.

"Light and dark are cues that help synchronize our circadian system to our environment," Decker said.

The same concept goes for why people experience jet lag -- when you're crossing time zones, your brain is preparing to fall asleep because it's dark in your time zone. "But if you're suddenly waking up and receiving new light, your brain's sleep-wake cycle becomes desynchronized, and it takes several days to be resynchronized," Decker said.

Decker recommends shift workers wear eyeshades when they sleep in the daytime to simulate darkness.

Room TemperatureIn the evenings, our core body temperature begins to drop, Decker said, and that drop in temperature is the signal that it's time to go to sleep. Taking a hot bath or drinking something warm raises their core body so that it's able to drop and people are able to get that physiological cue for sleep, he said.

As the night goes on and the morning begins to approach, our body temperature begins to gradually increase, until it reaches the room temperature and signals our brains to wake up, Decker explained.

"So if a room is too warm, our body temperature can actually increase," and can lead to us waking up, he said. "Keeping the room cool helps ensure that we have a better quality of sleep and that we allow our brain temperature mechanisms to do what they're supposed to do."